---
title: "What Is a Thesis Statement?"
url: https://www.learningloftinstitute.com/glossary/thesis-statement
source: Learning Loft Institute
language: en
updated: 2026-08-21
section: "Glossary › What Is a Thesis Statement?"
---
# What Is a Thesis Statement?
> **Answer.** A thesis statement is the one sentence in an essay that states the argument the rest of the essay will prove. It is a claim, not a topic: 'This essay will discuss Curley's wife' is a topic, while 'Curley's wife is presented as a product of the ranch's isolation, not its cause' is a thesis.
## Key facts
| | |
| --- | --- |
| Definition | A thesis statement is a single sentence stating the arguable claim an essay sets out to prove, placed early so a reader knows what is being argued. |
| Where students meet it | Grades 9 and 10 English, at the point where essays stop being marked as descriptions and start being marked as arguments, and in any IGCSE literature response whose opening paragraph is expected to commit to a reading. |
| Also known as | Line of argument, Argument statement |
## The three tests it has to survive
A thesis is easier to check than to write, and running three questions past a draft takes under a minute. Most weak theses fail the first one, which is also the quickest to apply.
If a sentence fails the first test it is a topic. If it fails the second it will produce a summary rather than an argument. If it fails the third the essay and its opening promise are describing two different pieces of work, and the marker will notice before you do.
- Could a reasonable person disagree with this? If not, it is a fact or a subject, not an argument.
- Does it say how or why, rather than only what? A thesis that stops at what produces paragraphs of retelling.
- Does it cover the whole essay and nothing beyond it? If the final paragraph is not covered by it, one of the two needs changing.
## Topic, question, claim: three different sentences
Curley's wife is a topic. How does Steinbeck present Curley's wife is a question — usually the one printed on the paper. The thesis is the third sentence, the answer to that question stated as a position. Students very often hand in the second sentence dressed up as the third, because restating the question feels like beginning.
The way out is to finish the sentence 'I am going to argue that...' and then delete the opening. Whatever remains is the thesis, and if nothing remains, the reading has not been decided yet, which is a genuinely useful thing to discover before the essay rather than during it.
## Where it goes, when to write it, what to call it
In school essays it usually closes the opening paragraph, after a sentence or two establishing the text and the question. That is a convention rather than a law, and the reason behind it is worth more than the placement: the reader should not reach the second paragraph without knowing what is being argued.
Write it after the evidence is gathered, not before. A first attempt is a working thesis, and an argument that changes while the essay is being written is a sign of thinking rather than a mistake — the fix is to rewrite the opening sentence to match the essay that actually appeared. It is also worth knowing that many British teachers say line of argument rather than thesis statement; the mark schemes differ in wording and ask for exactly the same thing.
## Questions
### How long should a thesis statement be?
One sentence, occasionally two if the claim genuinely has two parts. Length is rarely the problem. A thesis fails by being uncontroversial, not by being short, and a long one is usually a short one with a topic sentence and an apology attached to the front of it.
### Can a thesis statement be a question?
No. A question is what an essay answers, so a question in the thesis position leaves the answer unstated and the essay without a spine. If you have written one, answer it in a sentence and use the answer instead. That answer is the thesis.
### Should I write 'In this essay I will argue that...'?
It is useful while drafting and better deleted afterwards. 'Steinbeck presents Curley's wife as...' makes the same claim with more authority than 'In this essay I will argue that Steinbeck presents Curley's wife as...' The scaffolding helps you find the sentence; it weakens the sentence once found.
### What if my argument changes while I am writing?
Change the thesis. This happens constantly and is a good sign, not a problem, because it means the evidence pushed back. What cannot be left is a mismatch: an opening promising one reading and a conclusion delivering another. The last thing to check before handing an essay in is whether its first claim still describes it.
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